Resistance



Feb. 9 1926.

O. KI/-ERBYE RESISTANCE Filed Feb. 1.2.

Patented Feb. 9, 1926.

UNITED STATES PATENT OFFICE.

OLUF KIZERBYE, OF COPENHAGEN, DENMARK, ASSIGNOR TO AKTIESELSKABET ETO `ELECTRO CO., OF COPENHAGEN.

RESISTANCE.

Application filed February 12, 1924.

To all whom t may Concern:

Be it known that I, OLUF KIAZRBYE, subject of the King of Denmark, residing at No. 8 Oehlenschlagersgade, Copenhagen B, Copenhagen, Denmark, have invented certain new and useful Improvements in and Connected with Resistances, of which the following is a. specification.

.The present invention relates to an adjustable resistance which may be used to advantage in connection with the headlights of automobiles, where it is important to be able to vary the intensity of light. Most frequently two electric incandescent lamps are used here in each lantern, so that the one a powerful lamp is placed in the focus of the parabolic mirror, while another-the weaker lamp-is placed somewhat outside of the focus, the said two lamps being connected in such a manner with the lighting circuit of the carriage, that the driver by manipulation of a handle pro vided on the dash-board may alternately light and extinguish the two sets of lamps.

In order now to simplify this installation, the present invention, as mentioned above, has foigits object to Iinsert a variable resistance in the circuit of the bright lamps.. so that the driver by a simple manipulation may reduce the lighting intensity of these lamps so much, that they will have no blinding effect, and still will light sufficiently to illuminate the road surface in front of the vehicle. However, as it is well known to insert variable resistances in the circuits of incandescent lamps, the present invention has for its object merely a special construction of such resistances, inasmuch as for automobile use and other kindred purposes spe-cial requirements are necessary for these adjustable resistances in respect to durability, reliability and cheapness, which re.- quirements are not filled by the known devices for this purpose.

The invention is illustrated in the accompanying drawing,

Fig. l showing the apparatus proper 1n longitudinal section.

Fig. 9, the resistance proper viewed from the outside. l

From the drawings all parts which are not strictly necessary in o rder to understand the apparatus have been omitted.

Serial N0. 692,412.

Tightly compressed between these two discs 7 and 8 are a series of annular discs 9'consisting of conductive material, and corresponding spacing rings 10 of some insulating material such as mica, fibre, hard rubber and the like are inserted between the conductive rings.

Compression bolts 1l.

A rigid hollow cylinder is thus formed, the cavity 12 of which is filled with carbon grains 13. These carbon grains will offer a certain resistance to the passage of the current. i

In the partitions 3, 4 provided inside of the outer end walls 2 of a casing 1 two pins 5, 6 are journalled carried respectively by the discs 7 and 8.

Each ofthe conductive discs 9 is fitted with a lug 14, and the discs are turned relatively to each other in such a manner, that the lugs form a heliX as shown plainly in Fig. 2.

Between the two walls 3 and 4 a conductive rod 15 is provided outside of the cylinder in such a manner, that the lug 14 may come in contact with the said rod when the cylinder is rotated. The end of this rod is connected to a conductor 16, while another conductor 17 leads to a contact spring 18 rest-ing against the end of the pin 5.

Finally a handle or the like is provided on the pin 6 in order that the cylinder formed by the discs 9 and 10 may be rotated.

The apparatus is inserted in the circuit of the lamps, and only one single lamp is then provided at the focus of the reflector, and the current will now pass from conductor 17 and the contact 18 to the pin 5, which is conductively connected to the carbon grains 13, through these grains and the one annular disc 9 of which the lug414: is in contact with the rod 15, and from there through the saidrod and conductor 16.

If now the handle 19 is turned to one or the other side, then the lug 14 of another disc 9 nearer to or farther away from the pin 5 will touchthe rod 15, and as the current will thereby be forced to flow through the carbon grains for a shorter or longer is effected by internal distance, the resista-nce will becorrespond ingly larger or smaller.

The apparatus may be arranged in such a manner that after a revolution'has been made in one direction, so much resistance will have been inserted, that`tl1e lamps will be extinguished, or a lug may be omitted on the last disc 9, whereby the apparatus simultaneously may be used as a switch.

The construction described is intended to be used for variation of the lighting intensity of incandescent lamps, but the device may be used without essential modifications as starting resistance for electric motors, and especially owing to its simple construction it may be used for sewing machine motors, ventilator motors and the like.

Having now described my invention, what I claim as new and. desire to secure by Letters Patent is:

1. An adjustable resistance, adapted for regulation of the lighting intensity of incandescent lamps and for starting resistances and the like, comprising a support,

4an element mounted for rotary movement in said support, said rotatable element including annular discs formed of conducting material, spaced elements formed of insulating material and interposed between the end and intermediate conducting discs, granular carbon arranged within the discs and insulating members, means to clamp the several discs together, a conducting rod eX- tending substantially parallel tor the axis otl the rotatable elementand in spaced rela* tion thereto, and lugs carried by the conducting discs, theseveral lugs being hclically arranged around the rotatable element and adapted, during rotation of the latter to be successively brought into contact with the said rod.

2. An adjustable resistance as claimed in claim l characterized in that the rotatable member is movable into such position in respect to the rod as to interrupt electrical connection between the latter and said rotatable element. a

Inv testimony whereoi:l I atlix my signature.

OLUF KIZERBYE. 

